The neuropathology of experimental bovine spongiform encephalopathy in thepig

In an experimental study of the transmissibility of BSE to the pig, seven o f 10 pigs, infected at 1-2 weeks of age by multiple-route parenteral inocul ation with a homogenate of bovine brain from natural BSE cases developed le sions typical of spongiform encephalopathy. The lesions consisted principal ly of severe neuropil vacuolation affecting most areas of the brain, but ma inly the forebrain. In addition, some vacuolar change was identified in the rostral colliculi and hypothalamic areas of normal control pigs. PrP accum ulations were detected immunocytochemically in the brains of BSE-infected a nimals. PrP accumulation was sparse in many areas and its density was not o bviously related to the degree of vacuolation. The patterns of PrP immunola belling in control pigs differed strikingly from those in the infected anim als.